I am gonna vote no on that one. I could see the bungee or whatever rope is holding the bouy down getting tangled in the prop shaft, or around the rudder. But either one of those would be more of an annoyance than anything. At a lake I used to ski on all the time there was a number of turtles around, and we would occasionally hit them on accident and hear a large thud too.....but it never did anything to the hull, so I think you are safe.